Project Summary Gay, bisexual, and other men who have sex with men (GBMSM) are at high risk for HIV-1 acquisition, especially in rights-constrained settings such as Kenya, where men's access to HIV prevention has been impeded by homophobia, stigma, and discrimination. Pre-exposure prophylaxis (PrEP) has the potential to greatly reduce HIV acquisition risk in this key population, if accessible, sustainable PrEP programming with tailored, effective adherence support can be provided. To this end, close collaboration between PrEP program implementers and GBMSM-led community-based organizations is essential. In this R34 application, we propose (1) to identify multi-level barriers and facilitators that influence GBMSM's ability to engage in the PrEP continuum of care by examining socioecological factors that impact Kenyan GBMSM's lives, including sexual and PrEP-related stigma, sexual health promotion, and resilience, through qualitative work with PrEP- experienced and PrEP-nave GBMSM and peers engaged in HIV testing/counseling or PrEP programming; (2) to adapt and enhance a theory-based and culturally relevant PrEP support intervention called Shikamana PrEP that includes peer navigation and integrated ?Next Step Counseling? to promote sexual health protection strategies, including PrEP uptake and adherence, among GBMSM in Kisumu, following steps 1-6 of the ADAPT-ITT model (assessment, decision-making, adaptation, production, expert review, and integration of feedback) in collaboration with our GBMSM community partners; and (3) to determine the acceptability, feasibility, and safety of the Shikamana PrEP intervention and estimate initial effect size compared to standard of care on PrEP uptake and adherence assessed by drug levels over 6 months in a pilot randomized controlled trial. This proposal builds on the success of the Shikamana study, which developed a provider and peer support intervention that successfully increased the odds of plasma viral load suppression among HIV-positive GBMSM taking antiretroviral therapy, and the Anza Mapema project, which enrolled over 600 HIV-negative GBMSM in Kisumu for 12 months of follow-up in HIV prevention services and is currently following a PrEP cohort of 167 men for 12 months. Our experienced, productive multidisciplinary team of collaborators from the University of Washington, University of Michigan, and the Nyanza Reproductive Health Society, has expertise in the fields of HIV prevention and care (Drs. Graham, Otieno, and Bailey) and behavioral science and intervention design (Drs. Graham, Harper, Amico, and Simoni), and has partnered for this research with the NYARWEK Network of 23 community-based LGBTI organizations in the study area. We anticipate that results of the proposed research will have high impact by ensuring GBMSM involvement in the scale-up of effective PrEP programming for this key population in Kenya and providing a peer-led PrEP support model for GBMSM and other vulnerable and marginalized populations in African settings.